An object moving on the x axis with a constant acceleration increases its x coordinate by 80 m in a time of 5.0 s and has a velocity of +20 m/s at the end of this time. Determine the acceleration of the object during this motion.
A)(-1.6 m/s2)
B)+6.4 m/s2
C)+1.6 m/s2
D)(-2.0 m/s2)
E)(-6.4 m/s2)

Question

Quizplus · Accepted Answer

Using the kinematic equation 
$x = x_0 + v_0t + \frac{1}{2}at^2$
where
$x_0 = 0$ (initial position), 
$x = 80$ m (final position), 
$v_0 = 0$ (initial velocity), 
$t = 5.0$ s, and 
$v = +20$ m/s (final velocity)

We can rearrange the equation to solve for the acceleration, a:

$a = \frac{2(x-x_0)-2v_0t}{t^2} = \frac{2(80-0)-2(0)(5.0)}{(5.0)^2} \approx +1.6 	ext{ m/s}^2$

Therefore, the answer is C, +1.6 m/s2.

An Object Moving on the X Axis with a Constant